Plan Study: RoG (River of Grass)

J.F Bedard's Trailerable Cruiser

Article by J.F. Bedard

I’ve had this design in the back of my mind for a long time: an expedition micro that will accommodate two adults for a weekend or a single-hander for up to five days. It could take on some weather and deliver solid performance while doing so. For the crew it’s forgiving and predictable but fast and fun. Launch time should be minimal. As I’m contemplating entering the Everglades Challenge, she must draw eight inches or less, be rowing-friendly and beach-launchable unassisted; in other words, as small as possible.

The result is RoG (River of Grass), a 15-foot micro expedition cruiser.

Design Concept

Stability and weight are two overarching concepts of this design: Together they strongly define safety and performance but are potentially conflicting, so I took the approach of combining lead and water ballast. A 100-pound swing keel provides ultimate stability while 80 pounds of water in either of two wing tanks adds versatility. The result is a range of positive stability in excess of 100° and the ability to accommodate various conditions: In light-air or windless conditions, empty tanks will lighten the boat and reduce wetted surface. For enhanced performance, the windward tank is filled, which will result in a significant increase in righting moment as well as ability to pound through chop. Finally, both the keel and rudder are high-aspect ratio foils that minimize wetted surface while providing performance to windward. The rudder is balanced so will be light and responsive. Beanbag sailing will benefit from filling both tanks (which in effect means 160-pounds of water ballast, bringing the overall ballast to a respectable 260 pounds): the boat will now behave like a 25-footer; great for newbies, lazybones and exhausted raid-sailors.

Hull

A given was that this would be a chined hull, built of developable panels. I spent a lot of time comparing various iterations and it is clear that bringing the chine down close to the waterline increases stability significantly, hence the slab sides. Ditto for the blunt nose; but it’s a balancing act to achieve this while keeping the transom out of the water at all angles of heel and wetted surface to a minimum; as the latter is a strong indicator of light-air performance. So don’t be deceived by the boxy look, this is a powerful hull and can support a significant sail plan.

Rig

If there is one topic sailors love to argue it’s sail plan. Many aspects have to be juggled: center of effort, center of gravity, aspect ratio, versatility and simplicity (both to maneuver and rig) are but a few. I chose the cat ketch for a combination of these factors. Carbon spars, which have come down in price recently, make this rig quite attractive, and are a breeze to set up on the trailer. One-hundred and fifty square feet will bring the Sail Area-to-Displacement ratio to 24, somewhere between the Wayfarer and Goat Island Skiff, promising a fine ride to the thrill seeker.

Comfort & Convenience

The devil is in the details and a lot of time went into this part of the design. There is sitting headroom in the cabin and a forward table can be lowered in separate halves, to make bunks on either side. Two big self-bailing cubicles (and 4 cup holders!) in the cockpit two watertight lazarettes and ABYC-compliant dedicated gas locker, for grill/outboard tanks adds comfort and safety. Full-length oars are stowed under deck and out of the way, accessible via a small watertight transom hatch. The companionway is a hybrid kayak-coaming/sailboat-companionway hatch: It is large enough that one can reach the bow anchor and main mast while standing in the cabin, yet can be covered with stretch canvas or wood panels for spray/rain/sun protection in various configurations. Completely open in fair weather the cabin is closer to a dodger than an oven.

Safety

The boat is ABYC unsinkable, thanks to the use of flotation foam. She is designed to recover dry from any but the most catastrophic capsize. Indeed downflood angle is 108°, so no bailing for a tired crew. Centerboard and rudder systems are accessible and repairable underway, including keel-lift mechanism and rudder bolts. Both appendages will kick up undamaged upon grounding, and re-boarding after capsize is effortless via the transom.

Variations

The current design has got a cabin and modern rig, but could easily be reconfigured into an open daysailer, with or without ballast, and fitted with aluminum spars with a bit less sail area for a somewhat tamer beast and lower price tag. Or closed transom with inboard seats and backrests coupled with a balanced lug rig, for those who prefer more traditional esthetics.

Conclusion

RoG will pack a lot of punch in a small glove, both in terms of performance and safety. The ratios point to a fast racer-cruiser. She can be home-built, stitch and glue ply/epoxy, and from a pre-cut kit or from plans. More info at www.bedardyachtdesign.com or email jf.bedard@bedardyachtdesign.com •SCA•